Damp problems in sockets... solutions?

[OnlQQker]

What's the outside ground level, is it flush, below or higher than the internal ground floor?

And if the area is below ground level then is it prone to flooding/high water table


This chap is good at explaining brick/water absorption

 

[HappyHippyDad]

ventilationis necessary in old houses. might also help investing in a de-humidifier.

They have dehumidifiers in most rooms already. I think (like most have said), the only option is to spend a bit of cash and get the damp proof guys in.

 

[Zerax]

I've had a couple of places injected with chemical dpc... it worked very well, but you have to make sure that the person doing it actually cares about what they're doing... and does it properly.

I've also used some stuff called Zypex (I think) years ago... it looks like cement and you just mix with water to create a slurry which is then painted onto the wall... so handy behind backboxes after you've chased them out.

You have to be careful with really old places with lime mortar / render... as they are supposed to 'breathe' and using any sort of damp proofing will just cause more trouble !

 

[nicebutdim]

I've also used some stuff called Zypex (I think) years ago... it looks like cement and you just mix with water to create a slurry which is then painted onto the wall... so handy behind backboxes after you've chased them out.

Xypex

 

[buzzlightyear]

OK gentlemen and ladys just sold a house and this that I did having a bad damp.
1) chip all the plaster off 1mtr high
Spray walls with salt remover
2) inject a damp proof between the bricks two course high
3) slurry the walls with sbr
4) mix render with sbr
5 top coat with finish plaster
6) wait till 6 months paint walls after.

 

[telectrix]

OK gentlemen and ladys just sold a house and this that I did having a bad damp.
1) chip all the plaster off 1mtr high
Spray walls with salt remover
2) inject a damp proof between the bricks two course high
3) slurry the walls with sbr
4) mix render with sbr
5 top coat with finish plaster
6) wait till 6 months paint walls after.

that's good. should just about last till the buyer's cheque clears.

 

[DPG]

Friend of mine has house which he has owned for years. Lived in it initially then rented it out after that. Old terrace with solid walls and concrete floor. I've lost count of what he's spent on damp proof injection, cement rendering, removing floor and laying damp proof membrane etc. Mostly done by professional people. House still has damp issues now.

 

[buzzlightyear]

Most of the damp is tracking a cross from one wall to the other, where debris betwen the bricks. And need clearing out
And a problem on a bay window taken the render off in side and hoover all the crap out, I bet one on here will say why did I not remove the bricks out side, answer accie bricks.

 

[Macsamillion]

Were you testing from the board with all fixtures in place? If so I would split the legs and check if a particular one is dragging it down. In that situation i would immediately think the issue is not the wiring but the sockets. Is your reading of 0.3mohm with sockets ?

 

[Colin Jenkins 01]

I have a customer who lives in a grand old house which suffers from damp.

The ground floor sockets (2 different circuits) IR test at around 0.3Mohms L/N-E. This was actually 0.01Mohms but I have already done some fault finding and managed to improve it.

Most of the back boxes are very rusted and flaking to bits with moisture inside them. As stated, I have done some improvements to the sockets and boxes but this has only managed to get the IR up to 0.3Mohms (L/N-E). I have looked thoroughly for any more sockets/FCU's that I may have missed but I now feel the remaining fault(s) are within the walls, even though this doesn't make sense as I can't see how moisture would have got inside the cable (Its black/red metric PVC).

I think the existing cables have metal capping within the damp walls, but again, even if this capping is rusting I cant see how it will affect the PVC covered cable. The wiring is approx 25 years old

My questions are..

1. What can you do about damp? It's pointless to rewire as the damp problem will still be there. Are there ways to protect the boxes and sockets from damp?

2. What are the solutions if I cannot raise the IR above 0.3Mohms? I'm guessing I have to map out the entire circuit, and find every single fault, but then what? It's an immaculate house, surface trunking not an option, new cable in wall not really an option as existing damp problem already somehow affecting cables in walls (unless some kind of cable joints in walls which are affected).

3. Are these designed to be installed in the wall? 2 Gang 35mm PVC Flush Box Round Corners with 20mm Conduit KO White (Sold in 1's) - https://www.cef.co.uk/catalogue/products/1063228-2-gang-35mm-pvc-flush-pattress-box-round-corners-with-20mm-conduit-ko-white

Usually fault finding is easy. 1 fault, bit of IR testing, fix fault. In this case there are faults everywhere and not just in the actual sockets!

Hello HippyHappyDad. This will be a tough one to find. The cables themselves will not be the problem - they work ok in damp environments. As above, remove every fitting you can find, dry the cable ends and test individually. My suspicion would be buried choc bar connectors plastered directly into a damp wall and hidden from view; kitchen fitters occasionally perform this trick when a kitchen gets re-modelled. If the wall has been re-plastered, only the householder's knowledge might help with identifying the location of any redundant accessory that was removed. Sometimes moving the sockets up to 4ft above floor level gets them out of the damp zone. Sometimes, a surface box is better than a flush one for a damp wall. Possibly a nail in the wall has gone into a cable (the RCD should trip for this). All a bit of a PITA. Regards,
Colin Jenkins.